#define _CRT_SECURE_NO_WARNINGS 1
struct ListNode* removeElements(struct ListNode* head, int val)
{
    if (head == NULL)
    {
        return NULL;
    }
    if (head->val == val)
    {
        head = removeElements(head->next, val);
    }
    else
        head->next = removeElements(head->next, val);
    return head;
}